The first major objective of this research is to conduct a comprehensive comparative analysis of three needs assessment approaches: 1) the social indicators; 2) the key informants; and 3) the field survey. Perceiving the three assessment approaches as complimenting each other, we will assess each in terms of its cost, practicality and utilizability and provide judgments regarding its relative validity and reliability. The data for this analysis were collected during the 01 year and from prior field surveys. They are from: 1) field surveys (N equals 6500) conducted in seven counties in Florida (N equals 4500) and one county in Kentucky (N equals 2000); 2) the mental health demographic profile system of these same 8 counties; and 3) the key informant study cnducted in Kentucky during the 01 year. A second major objective is to test the relative effectiveness of individual social indicators as predictors of specific kinds of mental health problems. A third major goal is to prepare a series of short manuals directed toward the prefessional health planner which would present the relative merit of each of the three needs assessment approaches, provide cost-benefit statements, outline the techniques associated with their use by different types of planning agencies, discuss methods of analysis and interpretation and offer some guidelines for moving from the data analysis to the implementation of findings.